Apparatus for the manufacture of acetic acid



Jan. 22 1924.

H. w. MATHESON APPARATUS FOR THE MANUFACTURE OF ACETIC ACID Filed March15 2 Sheets-Sheet 1 1919 2 Sheets-Sheet 2 Jan. 22, 1924.

H. w. MATHESON APPARATUS FOR THE MANUFACTURE OF ACETIC ACID Filed March15,

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-HOWARDW. MATHESON, OF SHAWINIGAN FALLS, QUEBEC, CANADA, ASSIGNOR TOCANADIAN ELECTED PRODUCTS COMPANY LIMITED, 01" MONTREAL, QUEBEC,

CANADA.

Application filed March 15, 1919. Serial No. 282,883.

T 0 all whom it may concern Be it known that I, HOWARD W. MA'rr nsoN, asubject of the King of Great Britain, and resident of the town ofShawimgan Falls, in the Province of Quebec and Dominion of Canada, haveinvented certain new and useful Improvements in Apparatus for theManufacture of Acetic Acid, of which the following is a full, clear, andexact description.

This invention apparatus for the relates to improvements in manufactureof acetic acid from acetaldehyde, and the object of the invention is toprovide a highly eflicient, simple and inexpensive apparatus for themanufacture of acetic acid.

According to the invention, the aldehyde is oxidized in a kettle atsuitable pressure and temperature and the vapors rising from the vesselare led through condensers and then returned into the vessel for furtheroxidizing.

In the drawings vention;

Fig. 1 is a side elevation of the apparatus.

Fig. 2 is a plan view.

Fig. 3 is an elevation of the condensers.

ferring more particularly to the drawings, 11 designates a suitablyshaped vessel having a lining of aluminum or other suitable materialproof against the action of acetic acid in presence of oxygen and whichwhich illustrate the infurthermore does not act as a catalyst in thedecomposition or oxidation of aldehyde. This kettle is provided at thetop with a man-hole 12 and at the bottom with a discharge valve 13. Thevessel or kettle contains pipe coils of material having the samecharacteristics as the lining. It is preferred, in order to facilitatetemperature regulation, to employ two coils designated 14 and 14 whichare supplied with water from a main 15 through pipes 16, the flow beingregulatable by valves '17 A valve controlled connection 18 is pro- 45vided by means of which steam may be 1ntroduoed into one of the coils.The coils have individual outlet pipes 19. A valve controlled pipe 20 isprovlded for introducin acetaldehyde into the kettle and a second va vecontrolled pipe 21 containing a Venturi meter 22 is provided forintroducing air into the kettle. This pipe extends to the bottom of thekettle and is arran ed in a s iral coil 23, which is provided wit amultitude over substantial y the whole bottom area, so

that it will bubble up and be distributed uniformly through the aldehydeand will also blow on the catalystlying on or near the bottom of thekettle and keep the catalyst in suspension until complete solution ofthe catalyst occurs. With a kettle bottom of the shape shown and a pipecoil the perforations are preferably on the lower side of the coil todirect air downwardly and toward the bottom of the kettle, but as thedirection of the jets is primarily to avoid collections of sediment theactual direction must be such as to obtain this result. At the top ofthe kettle is a valve controlled inlet 24 having a funnel-shaped mouth25 into which the necessary charges of catalyst may readily be poured.The kettle is provided with a pressure gauge 26, a fluid level gauge 27and an indicating or recording thermometer 28. At the top of the kettleis an outlet 30 for acetic vapors and also a safety valve 31 from whicha pipe leads out of the building containing the apparatus. About mid-waybetween bottom and top, the kettle is provided with an inlet 32 forreturn of a mixture of acetaldehyde and acetic acid. It will be notedthat wherever practicable all the connections to the kettle are at thetop in order to avoid leakage of acid. In connection with each kettle isa water condenser 33 and 'a brine condenser 34. The water condenser issupplied with cold water through a pipe 35 and the warm water escapesthrough a pipe 36. The brine condenser is supplied with cool brinethrough a pipe 37 and the discharge is through a pipe 38. The interiorarrangement of these condensers may be of any suitable type. The outlet30 of the kettle is connected by a ipe 39 with the top of the condenser33. ear the bottom of the condenser 33 is a valve controlled pipe 40which leads into the upper part of the brine condenser. A valvecontrolled branch 41 from this pipe leads to a pipe 42 through whichvapors may be passed to a scrubber (not shown). Near the lower part ofthe condenser 34 is a valve controlled connection 43 leading into thepipe 41. By this arrangement, the condensed vapors from the watercondenser may be turned directly into the scrubber line 42 and the brinecondenser 34 completely short-circuited in case of a break down. A pipe44 leads from the bottom of the condenser 33 to draw 01? thecondensation products and a similar pi e 45 leads from the bottom of thebrine con enser 34. A valve controlled connection 46 is establishedbetween these pipes at the level of the condenser bottoms. The lowerends of the pipes 44 and 45 connect with a U-shaped pipe 47 leading tothe inlet 32 of the kettle. This newpipe extends downwardly a sufficientdistance and the condensers are sufficiently elevated with respect tothe kettle, so that the pipe forms a liquid seal between the kettle andcondensers preventing the liquid in the kettle discharging through thepipes 44 and 45 into the condensers but enabling the condensers todischarge into the kettle. It is obvious that since there is directconnection between the top of the kettle and the top of the condensersthe pressures in the kettle and condensers will be substantially equal.Connected to the outlet 13 is a valve controlled pipe 48 leading to anysuitable acid storage and also a valve controlled pipe 49 leading to asewer. An adjustable relief valve 50 is provided in the pipe 41 whichacts automatically if the pressure passes a predetermined int to relievethe pressure by discharge into the scrubber line 42.

The operation of the device is as follows The kettle is charged withaldehyde through the pipe 20, the level of liquid being indicated by thegauge 27. .The aldehyde line is closed. A suitable amount of catalyst ispoured into the kettle through the funnel 25 and the valve 24 is closed.Steam is admitted through the pipe 18 to the inner coil 14 to raise thetemperature of the aldehyde to a point at which the reaction Will takeplace satisfactorily. turned off and air is admitted in suitablequantity through the pipe 21. This air bubbles up from the bottom of thetank through the hot aldehyde and a certain amount of the aldehyde isoxidized into acetic acid. The reaction is accompanied with aconsiderable evolution of heat which is absorbed by passing waterthrough eitheror bothof the coils 14, 14*, the amount of water beingregulated as desired. Owing to the temper ature of the reaction, acertain'amount of the aldehyde and the formed acetic acid are vaporizeand pass through the pipe 39 to the water condenser 33. Vapor which doesnot condense in the water condenser is passed through the pipe 40 to thecolder brine condenser or in an emergency may be passed through thepipes 40 and 41 directly to the main 42 leading to the scrubber. Anyvapor not condensed by the brine condenser may be passed through theconnection 43 into the pipe 41 and thence to the scrubber. Thecondensation products of the condensers are returned through the pipes44 and 45 The steam is both coils,-

menace and the U-seal 47 into the reaction vessel 11. This condensationproduct is a solution of acetic acid in aldehyde, the strength of thesolution gradually increasing as the process continues. It-will thus beseen that the circulation will continue in the apparatus as lon ,as asuitable temperature is maintained in t e reaction vessel. Thetemperature is gauged by the thermometer and is controlled y regulatingthe-admission of water to the coils 14, 14 The pressure is controlledprimarily by regulating the admission of air and indirectly by thetemperature and secondarily by adjustment of the relief valve 50. Anyunforeseen rise in temperature which is not relieved through the valve50 may be relieved through the safety valve 31 before damage is done tothe apparatus. The pressure will in all cases be regulated to keep theboiling point of the aldehyde well above the temperature used. As thereaction continues, more and more of the aldehyde becomes converted'into acetic acid. When the acid solution reaches the desired degree'ofconcentration, the admission of air is sto ped and the reactionconsequently stops. 'Fhe temperature is lowered by continued circulationof cold water through the coils so that no more vapor passes to thecondensers. The drain outlet 49 is closed and the kettle outlet 13opened, so that the acid flows away through coils located in thereaction vessel, means for admitting a heating agent to onev of, saidcoils and for admitting a cooling agent to a pair of condensersconnected in series for the passage of vaporous and gaseous productsfrom the reaction vessel and ,connected in parallel for return flow ofcondensate to the reaction vessel, a U- I seal in the return betweensaid condensers and the reaction vessel,'a by-pass conduit forshort-circuiting one of said condensers, a valve for isolating thereturn flows of the condensers, and a pressure regulating gas dischargevalve at the discharge end of the condenser series beyond the by-pass.

2. An apparatus for the manufacture of acetic acid from acetaldehydecomprising a reaction vessel, an air pipe leading to the bottom of saidvessel and provided with means for directing air against the bottom ofthe vessel, means for adjusting and gauging the flow of air through saidpipe, a temperature controlling coil located in the reaction vessel,means for admitting a heating agent to said coil, means for admitting a,cooling agent to said coil, a reflux condensing apparatus connected withthe reaction vessel, means for preventing flow of liquid from thereaction vessel to the condenser, and a pressure regulating device atthe discharge end of the condensing apparatus being an adjustably loadedescape valve for gas.

3. An apparatus for the manufacture of acetic acid from acetaldehydecomprising a reaction vessel, an air pipe leadin to the bottom ofsaidvessel and provi ed with means for directing air a ainst the bottomof the vessel, means for ad usting and gauging the flow of air throu h.said pipe, a temperature controlling coi located in the reaction vessel,means for admitting a heating agent to said coil, means for admittingacoo ling agent to said coil, a reflux multistage condensing apparatusconnected to the reaction vessel, said condensing apparatus havingcondensate returns for the several stages thereof, means to prevent flowof liquid from the reaction vessel to any stage of the condenser, meansto by-pass a stage of the condensin apparatus, means to isolate theliquid dlscharge ofsuch by-passed stage from the reaction vessel andfrom the rest of the condenser, and a pressure regulating means disposedbeyond the last stage of the condensing apparatus and adapted to controlescape of gas from the system.

4. An apparatus for the manufacture of acetic acid from acetaldehydecomprising a reaction vessel, an air pipe leading to the bottom of saidvessel and provided with means for directing air against sedimentarymatter disposed upon or near the bottom of the vessel to maintain thebottom of the vessel substantially'clear of such sedimentary matter andto maintain the matter in suspension in the liquid contents of thevessel, means for adjusting and gauging the for preventing flow ofliquid from the reaction vessel to the condensing apparatus, and apressure regulating device at the discharge end of the condensingapparatus serving to control escape of gas from the system.

i n witness whereof, my hand.

I HOWARD W. MATHESON.

' 00 have hereunto set 1

